Conventional paperboard cartons for packaging milk, juice, and other beverage products are typically formed from a paperboard blank assembled in a rectangular open-ended configuration, which is then filled with the liquid contents and sealed with a gable or flat-folded top. The carton forming, filling, and sealing is done under sanitary conditions in lines of so-called "form/fill/seal" machinery. The industry has developed reclosable spouts for such cartons, typically in the form of plastic spout fitments which are sealed to the top end of the cartons. Examples of hinged-type spout fitments are shown in commonly-owned U.S. Pat. Nos. 4,705,197 and 4,770,325, both to Gordon and Kalberer. Other types of spout fitments include pull-open nozzles and screw caps. These reclosable spouts allow the cartons to be more easily opened and reclosed without leaking.
The plastic spout fitments are typically attached to the paperboard blanks by sealing a flange portion of the fitment to a heat-sealable coating or extrusion layer on the paperboard, by means of adhesives, heat sealing, or sealing with an ultrasonic horn. The attachment step requires an intermittent certain dwell time for aligning each fitment in position on a carton and applying the required adhesive, heat, or ultrasonic energy to the portion to be sealed. An example of indexing machinery for precise registration and sealing of fitments to cartons is shown in commonly-owned U.S. Pat. No. 4,846,915 of Keeler, Bombolevich and Sinocchi.
As reclosable spout fitments have come into widespread use, recent developments have been made in fitment sealing apparatus which synchronize the intermittent fitment sealing step with a continuous conveyor line used to supply cartons to form/fill/seal machinery. Examples of such fitment sealing apparatus are shown in U.S. Pat. No. 5,102,485 of Keeler and Bombolevich, entitled "Apparatus For Continuous Feeding And Synchronized Application of Fitments To Carton Blanks And Related Method", and U.S. Pat. No. 5,100,369 of Keeler, entitled "System For Continuous High Speed Application of Fitments To Carton Blanks And Related Method", both of which are incorporated herein by reference. In these examples, the fitments are formed with a flat shape and are supplied to the fitment sealing station from a web or roll.
It is also desirable to apply three-dimensionally shaped spouts, e.g. plastic pull-open nozzles or screw caps, to the cartons at high speed in order to supply a continuous line of fitted cartons to a form/fill/seal machine. One proposal for such an apparatus is shown in U.S. Pat. No. 4,788,811 of Kawajiri, Honda and Furukawa. The Kawajiri et al. sealing apparatus includes a suction holder which retrieves a three-dimensional fitment from the end of a supply chute, moves the fitment axially inside a carton blank assembled in rectangular tube configuration, inserts the spout portion of the fitment laterally through a hole die-cut in the carton wall, and holds the flange portion of the fitment against the heat-sealable coating on the internal side of the carton while an ultrasonic horn is advanced on the external side. This apparatus, however, has the problem that the complex movements required of the cap holder limit the speed at which the machinery can be operated, and, further, has a significant risk of mechanical breakdown or misaligment of the fitment.